MRI: Acquisition of an Atmospheric Pressure Ionization Mass Spectrometer for Measurements of Trace Gases and Secondary Organic Aerosol Components in Air

有了这个化学主要研究仪器计划的奖项，来自加州尔湾大学的Barbara Finlayson-Pitts教授和同事Michael Kleinman，Sergey Nizkorodov，Donald Blake和Eric Saltzman将获得一个大气压QTrap质谱仪，该质谱仪能够对气体和颗粒进行高灵敏度和特定的测量。该仪器能够进行串联实验，包括使用纳米解吸电喷雾电离（nano-DESI）、萃取电喷雾电离（EESI）、大气固体分析探针（ASAP）电离和大气压电离（API）对二次有机气溶胶（SOA）进行分子分析。该提案旨在加强各级的研究和教育，特别是在以下领域：（a）确定异戊二烯光氧化的产物和相对湿度对气溶胶成分的影响;（B）实时测量复杂的挥发性有机化合物-二氧化氮-臭氧混合物中形成的SOA颗粒的成分;（c）通过与傅立叶变换红外线（FTIR）测量的比较，阐明气溶胶质谱法（AMS）测量有机硝酸盐的效率;（d）测量烟草烟雾中的挥发性有机化合物;（e）测量异戊二烯光氧化产生的含氮挥发性有机化合物;（f）测定水相酸和醛的光化学氧化产物;（g）在新颗粒形成和生长期间实时测量气溶胶流管中的气态前体和产物;（h）实时测量来自α-蒎烯与臭氧、OH和硝酸盐反应的气态对伞花烃;（i）SOA的氧/碳比的测量和与来自高分辨率电喷雾电离质谱的结果的比较;（i）真实的─在作为北大西洋气体通量研究以及其他研究活动的一部分的航行期间，对丙酮和其他含氧有机物进行时间测量。光谱法（MS）是用于识别和表征嵌入在复杂基质中的少量化学物质的关键分析方法之一。在典型的实验中，组分流入质谱仪，在那里它们被电离成母离子及其碎片离子，并测量它们的质量。这种高灵敏度的技术可以检测和确定复杂混合物中分子的结构。具有串联能力的仪器通过进一步碎裂光谱仪中产生的离子提供额外的结构鉴定能力。该奖项提供的仪器将为几个部门的教师和学生提供使用该机构迄今为止尚未提供的现代仪器进行研究项目的机会。这项研究不仅将影响化学领域，而且还将提供有关大气现象的重要知识。该仪器还将用于几个实验室课程，以培训大量学生使用这一重要的分析技术。

With this award from the Chemistry Major Research Instrumentation Program, Professor Barbara Finlayson-Pitts from University of California Irvine and colleagues Michael Kleinman, Sergey Nizkorodov, Donald Blake and Eric Saltzman will acquire an atmospheric pressure QTrap mass spectrometer that is capable of highly sensitive and specific measurements of both gases and particles. The instrument is capable of carrying out tandem experiments involving molecular analysis of secondary organic aerosols (SOA) using nano-desorption electrospray ionization (nano-DESI), extractive electrospray ionization (EESI), atmospheric solids analysis probe (ASAP) ionization and atmospheric pressure ionization (API). The proposal is aimed at enhancing research and education at all levels, especially in areas such as (a) determination of the products of isoprene photooxidation and the effects of relative humidity on the aerosol composition; (b) real-time measurements of the composition of SOA particles formed in complex volatile organic compounds (VOCs)-nitrogen dioxide-ozone mixtures; (c) elucidation of the efficiency of aerosol mass spectrometry (AMS) for measurements of organic nitrates by comparison to Fourier Transform infrared (FTIR) measurements; (d) measurement of VOCs in tobacco smoke; (e) measurement of nitrogen-containing VOCs from isoprene photooxidation; (f) determination of products of photochemical oxidations of aqueous phase acids and aldehydes; (g) real-time measurement of gaseous precursors and products in an aerosol flow tube during new particle formation and growth; (h) real-time measurement of gaseous p-cymene from the reaction of alpha-pinene with ozone, OH, and nitrate; (i) measurement of oxygen/carbon ratios of SOA and comparison to results from high-resolution electrospray ionization mass spectrometry; (i) real-time measurements of acetone and other oxygenated organic species during a cruise that is part of a North Atlantic gas flux study as well as other research activities.Mass Spectrometry (MS) is one of the key analytical methods used to identify and characterize small quantities of chemical species embedded in complex matrices. In a typical experiment, the components flow into a mass spectrometer where they are ionized into the parent ion and its fragment ions and their masses are measured. This highly sensitive technique allows detection and determination of the structure of molecules in a complex mixture. An instrument with tandem capability provides additional structural identification power through further fragmentation of ions produced in the spectrometer. The instrumentation provided by this award will provide faculty and students in several departments the opportunity to pursue research projects using modern instrumentation not heretofore available at the institution. The research will impact not only the field of Chemistry but also provide important knowledge of atmospheric phenomena. The instrument will also be used in several laboratory courses to train significant numbers of students in the use of this important analytical technique.